1. Field of the Invention
This invention relates generally to power transmission mechanisms, and, more particularly, to hydraulic systems for transmitting the power generated by a prime mover to the wheels of a motor vehicle, thereby propelling the same, or to a load driving motor, thereby moving the load.
2. Description of the Prior Art
While various hydraulic systems have been proposed for use in the transmission of motive power from a prime mover such as an internal combustion engine or a battery powered electric motor to the wheels of the vehicle being propelled, such systems have gained little, if any, commercial significance. A wide variety of factors undoubtedly account for this lack of acceptance, including, of course, the characteristic inertia of industry in adopting innovations that deviate markedly from a widely used product such as the mechanically driven automobile. However, numerous technical problems also hindered commerical exploitation of prior art hydraulic propulsion systems. For example, most systems were bulky and consequently heavy; the tanks needed to store large volumes of hydraulic fluid required in low pressure systems occupied vehicle space needed for other purposes. If high pressure was used instead, the volume of fluid flow needed to propel the vehicle at reasonable speeds (with reasonable accelerating power) was not available, without massive pump installations. In addition, although a great deal of attention was given in prior art systems to harnessing the energy normally lost during braking or down hill driving, the apparatus needed to effect energy conservation was often too expensive, complicated and cumbersome to justify the desired result.
In view of the foregoing, it is the broad object of the instant invention to provide a power transmission mechanism capable of propelling a motor vehicle or other load at reasonable speeds and with reasonable accelerating power without the problems normally associated with similar low or high pressure systems known in the prior art.
Other objects of the invention are to enable the transmission of motive power from a prime mover to the wheels or propellers of the vehicle without requiring apparatus of undue size or weight, to provide in such apparatus the capability of capturing and storing energy normally wasted, in an efficient manner, for later use in propulsion of the vehicle, and to generally improve the efficiency of the entire system by allowing the prime mover to shut down during time periods when power is not required.